Imagine that I need to build a big Cuba application (it uses Gradle to manage dependencies and in the build produces a .war).
I need to dockerize both the build and the application. The latter is run in a Tomcat image in which the .war is copied.
The most of the dependencies remain actually unchanged between consecutive builds of the project, but the build seems to go over them each time, taking like forever...
I'd like to produce a custom Docker image from gradle:jdk8 (kinda) that imports all the Gradle dependencies.
his image will be used for consecutive builds to produce the .wars and will be rebuilt only when there is a change in the dependencies' versions.
Though, I'm quite new to Gradle and I don't know:
Any advice/suggestion? Is this possible? Hope my question is clear, but I have difficulties in explaining my aim. Ask me for better explication. Thanks in advance.
You mean that you want to build a Docker image for build runner (or build agent), right?
It's not possible to import the dependencies without building the project, because Gradle resolves dependencies lazily, only when they are needed. E.g. artifacts to build a CUBA theme are resolved only when web theme is built.
Yes, it's possible to re-use previously downloaded library artifacts (cached in ~/.gradle/caches) to build the project in a shorter time.
So in your case you need to create build runner's docker image by fully building your project once in a Docker container. Dependencies will be downloaded and cached in the file system. Then you can pull that image and use it again for subsequent builds, avoiding re-downloading artifacts.
If you change CUBA platform version in your project, you'll need to re-create the build runner image if you want to avoid downloading cuba-*.jar artifacts for every build.